Speaker input rating

[creatip123]

WTH?? Quality equals sensitivity now??

 

So....I guess the $180.000 Focal Utopia Grande EM is worse than say the $3000 JBL 5732.

 

Because Grande EM's sensitivity is only 94dB/2.83V/m (http://www.grande-utopia-em.com/en/utopia-3/specifications.php), while the JBL 5732's sensitivity is way higher, at 110dB (http://www.avlgear.com/jbl-5672bi-jbl-5732mhf-mid-high-frequency-section-for-5732-cinema-system/)

 

Well, I learnt something today, that's for sure....

[Lutkeveld]

And there is actually a limit on efficiency: when you apply 1 electrical watt the maximum you can get is 1 acoustical watt.

1 acoustical watt is 112dB radiated in a hemisphere (2pi). Then your speaker would be 100% efficient. 

The maximum I saw was on a huge (tapped) horn, around 40% IIRC.

[joppetie]

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Right. I've looked up the ratings. Here it is:

The Amplifier is rated for 2 channels of 55W @6Ω

The speakers are both rated for 100W @6Ω

Can I crank them, Yay or Nay?

[Lutkeveld]

Thermally: yes. Mechanically: probably not.

As said: turn down when it audibly distorts.

 

BTW: speakers don't have a power rating with ohms. It's just 100W's.

Amplifiers say X watts at X ohms because their output changes with impedance.

[joppetie]

Thermally: yes. Mechanically: probably not.

As said: turn down when it audibly distorts.

 

BTW: speakers don't have a power rating with ohms. It's just 100W's.

Amplifiers say X watts at X ohms because their output changes with impedance.

This label begs to differ:

[Lutkeveld]

That's the different between thermal and mechanical power handling. Thermal is 9 of the 10 times the highest number, so they put it on the sticker. People with a 'watt-fetish' love it, which is at least 75% of the market.

[joppetie]

That's the different between thermal and mechanical power handling. Thermal is 9 of the 10 times the highest number, so they put it on the sticker. People with a 'watt-fetish' love it, which is at least 75% of the market.

Right, so I'll just play it at whatever volume I want, unless I hear any distortion whatsoever.

Also, I thought it was bad to play at high volumes for long periods of time? (not just for your ears, but more wear on the components)

 

Thanks for the advice, anyway!

[Lutkeveld]

Right, so I'll just play it at whatever volume I want, unless I hear any distortion whatsoever.

Also, I thought it was bad to play at high volumes for long periods of time? (not just for your ears, but more wear on the components)

 

Yup, the distortion is the voice coil leaving the magnetic gap, leaving its linear zone resulting in distortion.

To give you a more visual presentation of this:

You apply voltage to the voice coil, resulting in it starting to create a magnetic field.

This magnet field opposes or attracts the permanent speaker magnet, making the cone move forward and backward.

When the voice coil hits the backplate (the thing under the magnet) it deforms. In a deformed state it can't move up and down anymore.

The power at which this happens is the mechanical handling, often not given by a speaker manufacturer.

Thermal handling, what's on the sticker, is how much power you can apply to the voice coil for a given time without it melting.

This is much higher, and thus used as a marketing number. Thermal handling is not an issue for home use.

Music is peaks and dips, the average of these peaks an dips is 10-20 times under peak. Meaning when you apply 20W of music power, the woofer thermally only needs to handle 1-2W. Thermals is only an issue in PA systems, where it will be driven to the max for longer periods of time. 

Often resulting in a bad case of power compression, but that are things that don't matter here.

 

Please excuse my long speech ;p

[frozeefrank]

wow .

so much miss informed ppl !

[handruin]

Right. I've looked up the ratings. Here it is:

The Amplifier is rated for 2 channels of 55W @6Ω

The speakers are both rated for 100W @6Ω

Can I crank them, Yay or Nay?

 

 

Within reason, yes.  Not all amps are made equal and some amps in receivers share resources not allowing them to cleanly get to their peak outputs.  Generally speaking it's better to have more wattage than less.  Having a 200W per channel amplifier at 6 Ohm drive a speaker rated to handle 100W at 6 Ohm would be the better/safer way to "crank them".  Clipping/distortion is harder on the speakers especially when driven hard than having additional wattage in the amplifier to handle the dynamic peaks that can occur in audio/music etc.  I'm not saying you can't damage the speakers with more wattage but I feel you'll do more damage with less watts than more watts within reason (e.g. driving a 100W speaker with 2000W amp at full power).  

 

For example, I driven an old pair of Cambridge Soundworks Model six bookshelf speakers with an Emotiva XPA-5 amplifier.  The amp weighs 70Lbs and has a 1,200VA toroidal transformer with 60,000uF storage capacitance.  This is a pretty good sized power supply for it to keep up at 200W x 5 channels @ 8 ohms (300W @ 4 ohms).  The point being, this has the reserves to be able to amplify up to the 200W before clipping.  I was able to drive the Model 6 speakers loud and hard without damaging them or any distortion for hours on end.  They're rated 20-150W.

 

Basically use your judgement and listen to how they sound.  If things don't sound good at loud volumes then either you're over-driving the amp or possibly the speakers.  Turn it back a bit to avoid damage to your speakers and enjoy.

[mr moose]

The amp weighs 70Lbs and has a 1,200VA toroidal transformer with 60,000uF storage capacitance. 

 

Is there an online calculator that converts an amps weight to power?

[handruin]

Not that I'm aware of. Why would you want that?

[creatip123]

Is there an online calculator that converts an amps weight to power?

 

It can be easily converted/calculated to kinetic power. Just need to know the speed/velocity the amp is moving at the point of impact....

[handruin]

Wolfgang alpha might help with that.

Since we're looking for odd conversion websites, is there also an online calculator that converts passive aggressive communication to amps?

[mr moose]

Wolfgang alpha might help with that.

Since we're looking for odd conversion websites, is there also an online calculator that converts passive aggressive communication to amps?

 

I thought you might actually link to something like this:

 

http://www.axiomaudio.com/aboutamplifiers